package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {
    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private IUserService userService;
    //查询共同关注
    @Override
    public Result queryCommon(Long id) {
        Long userId = UserHolder.getUser().getId();
        String key="follows"+userId;
        String key2="follows"+id;
        //根据key查询两个集合的交集
        Set<String> commonSet = stringRedisTemplate.opsForSet().intersect(key, key2);
        if ( commonSet==null|| commonSet.isEmpty()){
            return Result.ok(Collections.emptyList());
        }
        List<Long> userList = commonSet.stream().map(Long::valueOf).collect(Collectors.toList());
        List<User> users = userService.listByIds(userList);
        List<UserDTO> userDTOs=users.stream().map(user -> BeanUtil.copyProperties(user,UserDTO.class))
                .collect(Collectors.toList());//.collect为将拷贝结果收集

        return Result.ok(userDTOs);
    }

    /**
     * 关注/取关功能
     * @param followUserId，要关注的人的id
     * @param isFollow，关注/取关
     * @return
     */
    @Override
    public Result Follow(Long followUserId,Boolean isFollow) {
        Long userId = UserHolder.getUser().getId();
        String key="follows"+userId;
        //关注则插入数据，取关则删除数据
        if (isFollow){
          Follow follow=new Follow();
          follow.setUserId(userId);
          follow.setFollowUserId(followUserId);
          save(follow);

          stringRedisTemplate.opsForSet().add(key,followUserId.toString());
        }
        else {
            remove(new QueryWrapper<Follow>().eq("user_id",userId).eq("follow_user_id",followUserId));
            stringRedisTemplate.opsForSet().remove(key,followUserId.toString());
        }
        return Result.ok();
    }

    /**
     * 是否关注
     * @param followUserId
     * @return
     */
    @Override
    public Result isFollow(Long followUserId) {
        Long userId = UserHolder.getUser().getId();
        Integer count = query().eq("user_id", userId).eq("follow_user_id", followUserId).count();

            return  Result.ok(count>0);

    }
}
